Survival Motor Neuron (SMN) function in motoneuron development

运动神经元存活 (SMN) 在运动神经元发育中的功能

• 批准号: 9899326
• 负责人: Sharon L Amacher
• 金额: $ 36.49万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9899326
• 关键词: Adult; Affect; Amyotrophic Lateral Sclerosis; Axon; Binding Proteins; Biochemistry; Biology; Cells; Cessation of life; Child; Childhood; Complement; Complex; Data; Data Set; Defect; Dendrites; Development; Diagnosis; Disease; Failure; Functional disorder; Genetic; Genetic Diseases; Growth; Human; Immunoprecipitation; Infant; Inherited; Lead; Methods; Modeling; Molecular; Motor; Motor Neurons; Mutate; Mutation; Nature; Neurons; Neuropathy; Neurosciences; Paralysed; Phenotype; Positioning Attribute; Problem Solving; Process; Proteins; RNA; RNA Processing; RNA Transport; RNA metabolism; RNA-Binding Proteins; Research; Role; SMN protein (spinal muscular atrophy); Skeletal Muscle; Spectrophotometry; Spinal Diseases; Spinal Muscular Atrophy; Testing; Therapeutic; Tissues; Transgenic Organisms; Western Blotting; Zebrafish; cell type; design; experience; experimental study; imaging genetics; in vivo; infant death; innovation; insight; link protein; motor neuron function; mutant; nerve supply; novel; novel strategies; polarized cell; protein complex; synaptogenesis; targeted treatment; trafficking; transcriptome sequencing

Project Summary Understanding the mechanistic basis of motoneuron dysfunction and its role in motoneuron diseases would fill a major gap in neuroscience and advance new approaches for treating devastating diseases such as amyotrophic lateral sclerosis (ALS), hereditary motor neuropathy and spinal muscular atrophy (SMA). These diseases afflict over one hundred thousand adults, infants, and children per year in the US. ALS and SMA are particularly devastating diseases resulting in paralysis and death often within a few years of diagnosis. The genetics of these diseases indicates that motoneurons are particularly vulnerable to defects in proteins tasked with critical RNA processing functions. However, exactly why motoneurons are vulnerable to RNA processing defects is not understood. The scientific rationale for this project is to elucidate mechanistically how mishanding of RNAs can disrupt motoneuron function and lead to motoneuron death. Elucidating the motoneuron-specific RNA processing defects caused by these mutations is essential for understanding motoneurons in both normal and diseased conditions and will direct critically needed therapeutics. To tackle this issue, we focus on the ubiquitously expressed survival motor neuron (SMN) protein and the motoneuron disease SMA. SMA is a motoneuron disease that affects infants/children and is caused by low survival motor neuron (SMN) protein levels. SMN functions in many aspects of RNA metabolism. However, the critical RNA handling function of SMN in motoneurons is unresolved. Evidence supports that SMN interacts with various neuronal RNA binding proteins (RBPs) that stabilize and/or transport RNAs to axons and dendrites during development. Using unique zebrafish models that we have generated, we have shown that SMN is required for normal vertebrate motoneuron development including dendrite formation and motor axon outgrowth and arborization. This is a key finding and reveals that SMA is not a degenerative defect, but the motoneuron dysfunction is caused by poor motoneuron development leading to neuronal failure. We hypothesize that SMN associates with neuronal RBPs and their cargo RNAs in a developmentally regulated manner to direct motoneuron development including axon out growth and branching, dendrite formation, and synapse formation. To test this we will answer three essential questions: What SMN:RBP complexes are in developing motoneurons? How do defects in these RBPs affect motoneuron development? What RNAs are in these complexes, and how are they affected when SMN or the RBPs are missing or decreased? All of our experiments will be performed in vivo in motoneurons, the relevant cell type and use a broad range of experimental approaches such as biochemistry, mass spectrophotometry, RNAseq, single neuron imaging and genetics. Data from these experiments will have broad implications for understanding RNA involvement in normal motoneuron development, SMA, and other motoneuron diseases such as ALS. In addition, our approach will rigorously test the importance of SMN:RBP complexes and their associated RNAs revealing a fundamental molecular mechanism in motoneuron biology.

项目摘要 了解运动神经元功能障碍的机理基础及其在运动神经元疾病中的作用将填补 神经科学的主要差距和进步的新方法，用于治疗造成肌萎缩等毁灭性疾病 侧面硬化症（ALS），遗传性运动神经病和脊柱肌肉萎缩（SMA）。这些疾病困扰着 在美国，每年超过十万成年人，婴儿和儿童。 ALS和SMA尤其是 毁灭性疾病经常在诊断后的几年内导致瘫痪和死亡。这些的遗传学 疾病表明，运动神经元特别容易受到关键RNA任务的蛋白质缺陷 处理功能。但是，确切地 理解。该项目的科学理由是阐明机械机理的不当 RNA会破坏运动神经元的功能并导致运动神经元死亡。阐明运动神经元特异性 由这些突变引起的RNA处理缺陷对于理解两个正常的运动神经元至关重要 和患病的疾病，将指导急需的治疗剂。为了解决这个问题，我们专注于 普遍表达的生存运动神经元（SMN）蛋白和运动神经元疾病SMA。 SMA是一个 影响婴儿/儿童的运动神经元疾病，并由低生存运动神经元（SMN）蛋白水平引起。 SMN在RNA代谢的许多方面起作用。但是，SMN的临界RNA处理函数 运动神经元尚未解决。证据支持SMN与各种神经元RNA结合蛋白相互作用 （RBP）在发育过程中稳定和/或将RNA稳定和/或将RNA运输到轴突和树突。使用独特的斑马鱼 我们已经生成的模型，我们证明了正常脊椎动物运动神经元需要SMN 开发包括树突形成和运动轴突的生长和树皮化。这是一个关键发现， 揭示SMA不是退化性缺陷，但运动神经元功能障碍是由较差的Motoneuron引起的 发育导致神经元衰竭。我们假设SMN与Neuronal RBPS及其相关 货物RNA以开发调节的方式指导运动神经元开发，包括轴突 消除生长和分支，树突形成和突触形成。为了测试这一点，我们将回答三个 基本问题：哪些SMN：RBP综合体在发展运动神经元中？这些RBP中的缺陷如何 影响运动神经元的发展？这些综合体中的RNA是什么，在SMN或 RBP缺失还是减少？我们所有的实验将在运动神经元中进行体内进行 细胞类型并使用广泛的实验方法，例如生物化学，质量分光光度法， RNASEQ，单个神经元成像和遗传学。这些实验的数据将对 了解RNA参与正常运动神经元发展，SMA和其他运动神经元疾病此类疾病 作为ALS。此外，我们的方法将严格测试SMN的重要性：RBP综合体及其相关的 RNA揭示了运动神经元生物学中的基本分子机制。